1. Field of the Invention
The present invention relates to a cam device and, in particular, to a cam device that has an extended life and that is for use in a hinge assembly incorporated in an electronic apparatus.
2. Description of the Related Art
Use of a cam device in a hinge assembly is already a known art. Referring to Taiwan Patent No. M244497, a laptop hinge assembly is incorporated with a cam device to allow the hinge assembly to be opened at various positions. The cam device includes a cam member and a cam follower rotatable relative to the cam member. The cam member includes a recess, and the cam follower includes a protrusion that selectively disposes in the recess. Moreover, the protrusion can be partially disposed in the recess at various extents to enable the hinge assembly to be opened at various positions. Also, when the protrusion is gradually rotated out of the recess, the cam follower will be gradually moved axially to press resilient members. At the same time, the resilient members will impart resilient force to urge the cam follower against the cam member.
Generally, when the protrusion is completely disposed out of the recess, the hinge assembly is fully opened. Also, the protrusion has a maximum area of contact to bear weight of a cover of the laptop, for instance. However, when the protrusion is partially disposed in the recess, a contacted area therebetween is reduced, but weight of the cover is the same. Therefore, an increased pressure exists in the cam device, which damages the cam device.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.